fix(flutter): correct cursor scaling and Linux cursor clipping

Keep Linux/macOS bitmap sizing and painted cursor DPI conversion consistent, and derive hotspots from the actual scaled bitmap. Pad tall Linux native cursor buffers with transparency to preserve the lower half in the hardware cursor plane. Cover bitmap sizing, hotspots, artwork preservation, and painting with focused regression tests.
2026-09-19 10:51:01 +03:00 · 2026-09-10 21:31:24 +08:00
parent f5b98b32f2
commit f96d00d9d1
5 changed files with 260 additions and 23 deletions
--- a/flutter/test/cursor_paint_scale_test.dart
+++ b/flutter/test/cursor_paint_scale_test.dart
@@ -0,0 +1,96 @@
+import 'dart:io';
+import 'dart:ui' as ui;
+
+import 'package:flutter/widgets.dart';
+import 'package:flutter_hbb/consts.dart';
+import 'package:flutter_hbb/desktop/pages/remote_page.dart';
+import 'package:flutter_hbb/models/model.dart';
+import 'package:flutter_hbb/utils/image.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:get/get.dart';
+import 'package:provider/provider.dart';
+
+const _hotspot = Offset(4, 9);
+const _remotePosition = Offset(100, 80);
+const _canvasOffset = Offset(15, 10);
+const _canvasScale = 0.5;
+const _viewport = Size(200, 160);
+
+class _CursorModel extends ChangeNotifier implements CursorModel {
+  _CursorModel(this.image);
+
+  @override
+  final ui.Image image;
+  @override
+  double get hotx => _hotspot.dx;
+  @override
+  double get hoty => _hotspot.dy;
+  @override
+  double get x => _remotePosition.dx;
+  @override
+  double get y => _remotePosition.dy;
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+class _CanvasModel extends ChangeNotifier implements CanvasModel {
+  _CanvasModel(String style)
+      : viewStyle = ViewStyle(
+          style: style,
+          width: _viewport.width,
+          height: _viewport.height,
+          displayWidth: _viewport.width.toInt(),
+          displayHeight: _viewport.height.toInt(),
+        );
+
+  @override
+  final ViewStyle viewStyle;
+  @override
+  double get x => _canvasOffset.dx;
+  @override
+  double get y => _canvasOffset.dy;
+  @override
+  double get scale => _canvasScale;
+  @override
+  ScrollStyle get scrollStyle => ScrollStyle.scrollauto;
+
+  @override
+  dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
+}
+
+void main() {
+  for (final (style, zoom, dpr, scale) in [
+    (kRemoteViewStyleAdaptive, false, 2.0, 0.5),
+    (kRemoteViewStyleAdaptive, false, 3.0, 1 / 3),
+    (kRemoteViewStyleAdaptive, true, 3.0, _canvasScale),
+    (kRemoteViewStyleOriginal, false, 2.0, _canvasScale),
+  ]) {
+    testWidgets('$style zoom=$zoom dpr=$dpr keeps cursor scale and hotspot',
+        (tester) async {
+      final image =
+          (await tester.runAsync(() => createTestImage(width: 9, height: 18)))!;
+      addTearDown(image.dispose);
+      await tester.pumpWidget(MediaQuery(
+        data: MediaQueryData(devicePixelRatio: dpr),
+        child: MultiProvider(
+          providers: [
+            ChangeNotifierProvider<CursorModel>(
+                create: (_) => _CursorModel(image)),
+            ChangeNotifierProvider<CanvasModel>(
+                create: (_) => _CanvasModel(style)),
+          ],
+          child: CursorPaint(id: 'cursor-test', zoomCursor: zoom.obs),
+        ),
+      ));
+      final painter = tester
+          .widget<CustomPaint>(find.byType(CustomPaint))
+          .painter! as ImagePainter;
+
+      expect(painter.image, same(image));
+      expect(painter.scale, scale);
+      expect((Offset(painter.x, painter.y) + _hotspot) * scale,
+          _remotePosition * _canvasScale + _canvasOffset);
+    }, skip: Platform.isWindows && style == kRemoteViewStyleAdaptive && !zoom);
+  }
+}